1. Field of the Invention
The present invention relates generally to farm machinery. More particularly the present invention relates to a forage harvesting machine that includes a pickup header that is wider than the bale forming unit, providing the capability to pickup forage in a windrow that lies outside the side-boundaries of the bale forming unit.
2. Background Art
Forage may be harvested with a large round (cylindrical) baler, for instance. Such harvesting equipment, such as large round balers, include a pickup header for lifting the forage off the ground, from the windrow, and directing it into the harvesting equipment. Not infrequently, due to equipment wheels or wind, a windrow may become wider than the processing portion of the harvester, such as the bale-forming chamber of a large round baler. As well, when turning, it may become difficult or impossible to align the pickup header with the existing windrow. In either of these cases, the material outside the side of the processing portion (such as the bale-forming unit of a large round baler) needs to be moved in a direction perpendicular to the windrow, as well as being picked up, in order to be positioned to correctly engage the processing elements.
In a large round baler, the material that is picked-up by the header is transported to the bale forming chamber for processing, for being compacted into a round bale. Many models of round balers are manufactured, typically either fixed chamber balers or variable chamber balers. The fixed chamber balers include a bale forming chamber of a fixed bale diameter, where the material is not significantly compacted until the bale reaches the bale diameter. The variable chamber balers include a bale forming chamber of variable diameter, and the material is compressed as it is formed. Both types typically are mounted on a 2-wheel chassis, to be pulled by a tractor.
The location of the pickup header relative to the bale forming chamber is important for both types of round balers, as minimizing the distance in which material travels between the pickup and the bale forming chamber reduces potential negative affects. These negative affects include the potential for undesirable movement, like material being affected by strong cross winds, and damage caused to the crop, an example being leaf loss for alfalfa. For variable chamber balers this relationship is more critical as the pickup tines or teeth act on the crop material when beginning to form a small bale, as it begins to be compacted and the bale begins to be formed. The location of the pickup will thus affect the capability of the baler to properly start forming a bale.
The location of the pickup header relative to the baler wheels is also important because the wheel/tire diameter is fairly constant. If the header is close to the baler wheels then the baler wheels will assist to control the ground clearance of the pickup tines. In balers where the header is located a significant distance from the baler wheels, the pickup header typically has separate gauge wheels to control the ground clearance.
Many models of balers are available that include a pickup header that is wider than the bale forming chamber. In many of these currently available machines there is a feeding device between the pickup and the inlet to the baler, an example of which can be seen in U.S. Pat. No. 6,314,708. This feeder has been found to be necessary to achieve desired feeding capacity, and to provide the necessary feeding force to achieve desirable performance. However, this extra component causes the pickup to be moved relative to the baler wheels, causing more difficult control of the ground clearance of the pickup header. It also requires an additional drive system with the associated cost and complexity.
A wide pickup header for a large round baler is disclosed in European Patent #0064112 in which short augers, one on each side of the pickup header, direct the forage into the center so it can enter the bale-forming chamber of the baler.
In various locations on the pickup header, teeth or tines of varying rigidity are advantageous, enhancing the pickup and delivery of the forage material to the processing portions of the harvesting equipment. A round baler having stiff teeth is disclosed in U.S. Pat. No. 5,394,682. Indications in this patent are that the use of stiffer than usual teeth at the outside ends of the pickup header improves pickup and delivery of the forage to the round baler.
There is, therefore, a need for a method and apparatus for providing for a wide pickup header for forage harvesting that does not require that the header be relocated away from the wheels of the harvesting equipment. There is a further need for a variety of teeth to be used across the width of the header.